Are there any good instructional DVDs or guides, especially for injured people?

Hello all!

A friend of mine has been taking yoga classes for a couple of months, and enjoying it. But in May she’ll be undergoing (fairly mild) surgery on her lower back/buttocks area. I was hoping one of you guys would have a good suggestion for a yoga DVD that she could do – any good yoga DVDs would be nice, but especially something that has some milder/reduced-mobility exercises. The spiritual side isn’t important, just the movements.

So, which yoga DVDs have you guys found to be the best? Recommendations would really be appreciated.